登录到stdout的最简单方法:

import logging
import sys
logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)

所有日志输出都由处理程序处理;只需将logging.StreamHandler()添加到根日志记录器。

下面是一个配置流处理程序的例子(使用stdout而不是默认的stderr)，并将其添加到根日志记录器:

import logging
import sys

root = logging.getLogger()
root.setLevel(logging.DEBUG)

handler = logging.StreamHandler(sys.stdout)
handler.setLevel(logging.DEBUG)
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
handler.setFormatter(formatter)
root.addHandler(handler)

可以使用多个处理程序。

import logging
import auxiliary_module

# create logger with 'spam_application'
log = logging.getLogger('spam_application')
log.setLevel(logging.DEBUG)

# create formatter and add it to the handlers
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')

# create file handler which logs even debug messages
fh = logging.FileHandler('spam.log')
fh.setLevel(logging.DEBUG)
fh.setFormatter(formatter)
log.addHandler(fh)

# create console handler with a higher log level
ch = logging.StreamHandler()
ch.setLevel(logging.ERROR)
ch.setFormatter(formatter)
log.addHandler(ch)

log.info('creating an instance of auxiliary_module.Auxiliary')
a = auxiliary_module.Auxiliary()
log.info('created an instance of auxiliary_module.Auxiliary')

log.info('calling auxiliary_module.Auxiliary.do_something')
a.do_something()
log.info('finished auxiliary_module.Auxiliary.do_something')

log.info('calling auxiliary_module.some_function()')
auxiliary_module.some_function()
log.info('done with auxiliary_module.some_function()')

# remember to close the handlers
for handler in log.handlers:
    handler.close()
    log.removeFilter(handler)

请参阅:https://docs.python.org/2/howto/logging-cookbook.html

您可以为文件和stdout创建两个处理程序，然后创建一个记录器，其中的handlers参数为basicConfig。如果两个处理程序有相同的log_level和format输出，这可能会很有用:

import logging
import sys

file_handler = logging.FileHandler(filename='tmp.log')
stdout_handler = logging.StreamHandler(stream=sys.stdout)
handlers = [file_handler, stdout_handler]

logging.basicConfig(
    level=logging.DEBUG, 
    format='[%(asctime)s] {%(filename)s:%(lineno)d} %(levelname)s - %(message)s',
    handlers=handlers
)

logger = logging.getLogger('LOGGER_NAME')

记录文件和stderr的最简单方法:

import logging

logging.basicConfig(filename="logfile.txt")
stderrLogger=logging.StreamHandler()
stderrLogger.setFormatter(logging.Formatter(logging.BASIC_FORMAT))
logging.getLogger().addHandler(stderrLogger)

我简化了我的源代码(其原始版本是OOP并使用配置文件)，为您提供了@EliasStrehle的一个替代解决方案，而不使用dictConfig(因此最容易与现有源代码集成):

import logging
import sys


def create_stream_handler(stream, formatter, level, message_filter=None):
    handler = logging.StreamHandler(stream=stream)
    handler.setLevel(level)
    handler.setFormatter(formatter)
    if message_filter:
        handler.addFilter(message_filter)
    return handler


def configure_logger(logger: logging.Logger, enable_console: bool = True, enable_file: bool = True):
    if not logger.handlers:
        if enable_console:
            message_format: str = '{asctime:20} {name:16} {levelname:8} {message}'
            date_format: str = '%Y/%m/%d %H:%M:%S'
            level: int = logging.DEBUG
            formatter = logging.Formatter(message_format, date_format, '{')

            # Configures error output (from Warning levels).
            error_output_handler = create_stream_handler(sys.stderr, formatter,
                                                         max(level, logging.WARNING))
            logger.addHandler(error_output_handler)

            # Configures standard output (from configured Level, if lower than Warning,
            #  and excluding everything from Warning and higher).
            if level < logging.WARNING:
                standard_output_filter = lambda record: record.levelno < logging.WARNING
                standard_output_handler = create_stream_handler(sys.stdout, formatter, level,
                                                                standard_output_filter)
                logger.addHandler(standard_output_handler)

        if enable_file:
            message_format: str = '{asctime:20} {name:16} {levelname:8} {message}'
            date_format: str = '%Y/%m/%d %H:%M:%S'
            level: int = logging.DEBUG
            output_file: str = '/tmp/so_test.log'

            handler = logging.FileHandler(output_file)
            formatter = logging.Formatter(message_format, date_format, '{')
            handler.setLevel(level)
            handler.setFormatter(formatter)
            logger.addHandler(handler)

这是一个非常简单的测试方法:

logger: logging.Logger = logging.getLogger('MyLogger')
logger.setLevel(logging.DEBUG)
configure_logger(logger, True, True)
logger.debug('Debug message ...')
logger.info('Info message ...')
logger.warning('Warning ...')
logger.error('Error ...')
logger.fatal('Fatal message ...')